The present invention relates in general to a fruit orienting device for use with automatic sorting equipment that properly positions fruit or other produce, such as apples, for quality inspections.
Considerable effort has been placed on developing nondestructive sensor techniques for sensing the internal and surface quality of apples. Examples of these techniques include optical imaging systems for detecting bruises and other surface defects on the apples, and firmness testing devices which determine the firmness of an apple by tapping its surface, and sensing resulting acoustic vibrations therein. To work properly, both of these techniques require that the tests be performed on the apple's cheek. In the optical imaging technique, this requires that the imaging system be able to discriminate between the bruises or other surface defects, and the apple's stem or calyx.
One known technique for discriminating between surface defects and the stem or calyx is to employ complicated algorithms which can differentiate the concave surfaces around the stem/calyx ends from blemishes on the rest of the convex apple surface. Unfortunately, the use of such complicated algorithms slows down the apple sorting process, and this is unacceptable because the fruit packing industry requests that apples must be sorted at rates of 6-10 apples per second.
A more promising solution to this problem is to orient the apples prior to being imaged so that only the apple cheeks will be viewed by the imaging optics. This usually necessitates that the apples be oriented on a conveying device with their stem axes horizontal so that the apples can be rolled beneath the imaging optics, first for a preinspection for proper orientation with a reroute of improperly oriented fruit back to the beginning of the orientation process, and then for an inspection of the apple cheeks for bruises and other surface defects. This appears to be the most promising technique, for it eliminates the need for time consuming complex algorithms. In addition, this technique must be employed with firmness measuring devices and other quality measuring devices since such devices do not employ any optical means by which the cheek of the apple can be discriminated from the stem or calyx.
Unfortunately, all previously known techniques for orienting apples so that their stem axes are horizontal do not reliably orient the apples in the desired manner. For example, one known device employs a plurality of rollers which contact an apple at three locations on its surface. One of the rollers is a cylindrical roller that is driven to cause the apple to rotate so that its entire surface can be viewed by the imaging system. The other two rollers are positioned adjacent to the cylindrical roller on a common shaft, and are cone shaped with tapered apple engaging surfaces that tend to hold the apple between these two rollers. Although this device is capable of orienting various types of apples with their stem axes in a horizontal direction, it does not do so quickly and dependably, and often cannot maintain the proper orientation if and when it is achieved.